Disallow tests with identical titles as it makes it hard to differentiate them.
import test from 'tape';
test('foo', t => {
t.pass();
});
test('foo', t => {
t.pass();
});
import test from 'tape';
test(t => {
t.pass();
});
test('foo', t => {
t.pass();
});
test('bar', t => {
t.pass();
});